Does Plan B Work During Ovulation? Here’s What You Must Know Before Relying on It

Does Plan B work during ovulation? That’s one of the most common and confusing questions women ask after unprotected sex. Timing truly matters when it comes to emergency contraception. Plan B, also known as the “morning-after pill,” works best before ovulation by preventing the release of an egg. But what happens if you take it when ovulation has already started?

In this article, we’ll clearly explain how Plan B works, what happens if you use it during ovulation, and what other options you can consider when the timing isn’t in your favor.

Does Plan B Work During Ovulation?

No, Plan B (also called the morning-after pill) is not effective and does not work during ovulation. Though this contraceptive pill is designed to delay the process of ovulation (release of a mature egg from the ovary), it may fail considerably if ovulation has already occurred. In case ovulation has started, the egg will be released, which is then fertilized by the sperm cells, regardless of whether you have taken the pill. Hence, Plan B isn't a reliable emergency contraception to prevent pregnancy.

It is crucial to know that this pill is highly effective when it is taken within 72 hours of having unprotected sex. So, be mindful of timing.

Plan B's effectiveness depends only on how soon it is taken:

• Within 24 hours: About 95% effective

• Within 72 hours: About 89% effective

• After 72 hours: Little effective, particularly if ovulation has started

But within this window, the timing of your ovulation plays a major role.

Here's a table for a quick recap:

How does Plan B work?

Plan B consists of levonorgestrel, an artificial hormone that is similar to progesterone. It works by:

• delaying or preventing ovulation, which is the release of a mature egg from an ovary, a study says.

• making it challenging for sperm cells to reach the mature egg.

• stopping that one fertilized egg from implanting in the uterus. (This is less specific and not the primary action of Plan B).

How well it works can be impacted by the following factors:

• Time: The sooner you take Plan B after unprotected sex, the more or highly effective it is. 

• Weight: Give less effects for people with a weight of more than 165 pounds. 

• Previous Use: If you have used Plan B within the last 3 months, its effectiveness might be reduced slightly. 

The primary action of Plan B is to stop ovulation. One ovulation started; this pill will be ineffective. 

What happens after taking Plan B?

If you are bothered about whether Plan B works after one day of Ovulation, then be sure it does not. Besides, taking a morning pill would not affect your body negatively, but you may still become pregnant. It happens due to Plan B's ability to delay Pregnancy. If you are already ovulating, then an egg gets released before. Furthermore, sperm that live in the body for 6 days may reach it at any time.

Researchers have also speculated that emergency contraceptive pills such as Plan B may not be effective if taken on the day of Ovulation or sometimes later. Thus, it is essential to be alert regarding the use of contraception if not want to have a child.

How To Know If You Are Already Ovulating?

It is tough to confirm you are ovulating if you do not use ovulation predictor kits or track basal body temperature. Ovulation generally occurs around 14 days of the 28-day menstrual cycle. However, this duration can vary from one woman to another and the total days of the cycle.

The potential signs of ovulation are:

• Clear and stretchy cervical mucus

• Mild abdominal or pelvic pain

• Light spotting

• Increased libido (sex desire)

• Slight rise in basal body temperature

• Heightened sense of smell or sensitivity to certain odors

• Breast tenderness

• Feeling bloated

If you experience any of these signs, you are ovulating, but they may not be present in everyone. Tracking these symptoms can help you know whether Plan B is a reliable contraceptive option or not.

What If You Have Already Taken Plan B During Ovulation?

If you have taken Plan B or the morning-after pill, but suspect that you are ovulating, Plan B will not show any effects, as an egg has been released. In such cases:

• Consider using a copper IUD within five days of unprotected sex.

• Take a pregnancy test if your period is delayed, that is, late by more than one week.

• Wait for your next period, as this pill can sometimes cause irregular bleeding.

What else can you do during Ovulation to prevent Pregnancy?

If the ovulation process has started, the released egg undergoes fertilization, and Plan B can't reverse or stop it, as its work is to delay ovulation. In such a case, using other emergency contraception methods can be helpful. Those emergency contraception methods include:

1. Copper Intrauterine Device (IUD):

• The most reliable emergency contraception method, which is more than 99% effective.

• Can be used for up to 5 days after engaging in unprotected sex.

• Prevents sperm cells from reaching an egg and fertilizing it.

2. Ella (Ulipristal Acetate):

• The prescription-only pill is around 85% effective.

• Can be used for up to 5 days after unprotected sex.

• Works more effectively than Plan B during the fertile window. 

These contraceptive pills might show fewer effects if you:

• take them late

• vomit the pill out within 3 hours of taking it

• weight 70 kg

• have a BMI of more than 26 kg/m2

• are taking some medicines

Talk to your doctor for proper information regarding the use of these pills.

Does Plan B Work After Ovulation?

No, Plan B or the morning-after pill does not work after ovulation. It is designed to delay ovulation to prevent pregnancy. If you have already ovulated in the last 24 hours, this pill will show no effects, but the chances of pregnancy are lower. The only emergency contraceptive method that is effective after ovulation is the copper IUD, which helps prevent pregnancy up to 5 days of unprotected sex. Copper helps push back sperm cells and prevent them from fertilizing the mature egg.

The effective way to prevent pregnancy is to use these forms of birth control:

• Birth control pill (daily)

• Intrauterine Devices (IUDs)

• Condom

• Vaginal ring

• Patch

• Shot

• Implant

Understanding your menstrual cycle and ovulation period can help you know when Plan B will be effective after engaging in unprotected sex. 

What are the Signs that Plan B did not work?

These signs show that Plan B or the morning-after pill does not show any effects:

• Missed period for more than 1 week.

• Early pregnancy symptoms include nausea, mood changes, vomiting, fatigue, or breast tenderness.

• Spotting or light bleeding (but it is not always the case)  

• Abdominal pain or cramps

• Vomiting within 2 hours of taking it

It is crucial to understand that Plan B is not always 100% effective. If you find any symptoms familiar, seek medical attention for proper evaluation. 

Is Plan B safe?

Plan B is highly safe. Reports say that women who took Plan B  had no severe side effects. In addition, periods may come earlier or later; for some, it can be heavy, while others may complain of lighter periods. So, it is just a minor side effect that does not need any medical intervention. Still, an individual must speak with their doctor if something is going wrong with their body.

Side Effects of Using Plan B (Morning After Pills)

Fortunately, Plan B is a well-tolerated drug, and people may have mild side effects at times. It may make you sick or vomit, which is fine.

Let us have a look at the Plan B side effects:

• Breast Tenderness

• Vomiting

• Nausea

• Irregular or Heavy Periods

• Headache

• Stomach Pain or Cramps

• Dizziness

• Feeling Fatigue

What If You Are Not Sure About Ovulation?

If you are unsure about whether you have already ovulated, it is recommended to take Plan B immediately. This is because the effectiveness of this pill is highest when it is used instantly. But as the timing of ovulation can fluctuate because of factors such as irregular cycles, illness, or stress, it is challenging to predict the full accuracy. If you suspect you are ovulating, consider using more effective emergency contraception options, like a copper IUD that is inserted for up to 5 days after unprotected sex.

Moreover, use tracking methods, like ovulation predictor kits, to find out the increase in luteinizing hormone and track basal body temperature, and changes in cervical mucus.

How To Track Your Ovulation Cycle?

Tracking the ovulation cycle (which basically occurs around 14 days of a 28-day menstrual cycle) can help plan or prevent pregnancy. Here are the common methods to track your ovulation cycle:

1. Calendar Method: 

• Note down the first day of your menstruation or period every month. 

• Count the days between your periods to know the length of your menstrual cycle. 

• This method is not helpful for females struggling with irregular periods.

2. Ovulation Predictor Kits (OPKs): 

• These home tests can help detect an increase in luteinizing hormone (LH), which predicts ovulation. 

• Follow the instructions carefully mentioned in the kit to collect and test the collected urine. 

• If the result is positive, it means that the ovulation phase can occur within 24 to 36 hours. 

3. Basal Body Temperature (BBT): 

• Take your body temperature each morning with the help of a basal thermometer. 

• Record it in your notebook or an app. Note down the rise and fall before and during ovulation.

• Your basal body temperature will rise slightly after ovulation. 

4. Cervical Mucus Observation: 

• Check the consistency of the vaginal discharge or cervical mucus throughout your menstrual cycle. 

• As the ovulation cycle approaches, cervical mucus becomes clear and stretchy, and also looks like egg white, known as "fertile cervical mucus." 

5. Ovulation Tracking Apps: 

• Several apps, such as Period Tracker, Flo, and Clue, are available that can be useful in tracking the ovulation cycle. 

• These apps assist with recording of the period, basal body temperature, OPK results, and other ovulation-related symptoms. 

6. Monitoring Other Physical Symptoms of Ovulation

• Mild pelvic pain, one-sided twinges

• Slight increase in basal body temperature (BBT)

• Breast tenderness

• Increased libido (sex drive)

Note: Use these methods together to track your ovulation cycle more accurately. If you have been trying to conceive and are unable to get positive results, consult a gynecologist or obstetrician. 

When to Take a Pregnancy Test?

It basically depends on when the periods have started. But periods are not always consistent, so it can be challenging to know. In general:

• If you regularly track your cycle and your period is a week late, take a pregnancy test. But, results may be less accurate, as an early test might give false negative results because human chorionic gonadotropin (hCG) levels may not be sufficient.

• If you have taken Plan B, wait for about 3 weeks to take a pregnancy test.

• On the other hand, if you have not taken Plan B after unprotected sex, take a pregnancy test after two weeks of sex.

You should retake the test after some weeks of the first test to double-check the pregnancy result.

How Can You Terminate a Pregnancy?

Generally, medical and surgical options are recommended to terminate pregnancy. However, they differ based on where you live and the duration of your pregnancy. If you live in the United States, 12 states have banned abortions with some exceptions.

Here are the options:

1. Medical Options:

• It involves the use of two medications, such as mifepristone and misoprostol.

• You can take abortion pills until 11 weeks after the first day of the last period. But the success rate reduces after 7 weeks.

2. Surgical Options:

In some cases, the healthcare professionals suggest surgical abortions when pregnancy reaches beyond 16 weeks after the last period. Here are the 2 types of surgical abortions recommended by a doctor:

Suction abortion, or vacuum aspiration:

• It involves the use of a suction tool to get rid of pregnancy tissue from the uterus.

• The surgery is performed around 14 weeks of pregnancy. 

Dilation and Evacuation (D&E):

• It involves the use of surgical instruments, like a curette and forceps, to remove the pregnancy tissue from the uterus by dilating the cervix.

• This procedure is performed after the first trimester of pregnancy, which starts around 14 or 16 weeks. 

Important Recommendations

Here are the important things recommended for women who are considering Plan B:

1. Timing is Key:

Take Plan B immediately after engaging in unprotected sex. It should be used within 72 hours, as its effectiveness reduces with time.

2. Consult a Healthcare Provider:

If you are not sure about whether you are ovulating or if Plan B is the appropriate option for you, seek professional guidance for personalized advice.

3. Understand Limitations:

Understand that Plan B works less effectively during the ovulation phase. So, consider alternative methods of emergency contraception, like a copper IUD, if required.

4. Regular Contraception:

Do not use Plan B as a regular form of contraception. Seek help from a gynecologist to find the right contraceptive method that is suitable according to your health needs and lifestyle. 

Bottom Line

So, does Plan B work during ovulation? The answer is no, as Plan B primarily functions by delaying ovulation and is less effective once ovulation has begun. To avoid the need for emergency contraception, it's a good idea to talk to your doctor about various birth control options. After using Plan B, consider taking a pregnancy test to ensure peace of mind. While pregnancy is a significant life event, it’s best when it happens intentionally.

Also Read: What Happens After Ovulation? 8 Signs When Ovulation Is Over

DISCLAIMER: This content is intended for educational and informational purposes only, and it doesn't comprise medical advice. Always consult a gynecologist for effective and safe use of any type of contraception to prevent pregnancy after unprotected sex.